Concrete bridge pier and pier foundation



Sept. 3, 1929.

C. A. P. TURNER CONCRETE BRIDGE PIER AND PIER FOUNDATION Filed Dec. 21.1927 F E h a E C .AR TURNER.

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Patented Sept. 3, 1929.

UNITED STATES CLAUDE A. r. TURNER., on MINNEAPOLIS, MINNESOTA. y

CONCRETE BRIDGE :PIER AND PIER FOUNDATION.

Application filed December 21, 1927. Serial No. 241,649.

My invention relates in general to that class of concrete bridge piersand pier foundations which, like those of my Letters Patent No. 1,563,676, are commonly sunk in deep water through mud or quicksand to hardbottom by the open dredge method. It relates especially to that class ofthese foundations which are floated to position before completion andare righted by ballast While afloat and while being sunk. It is a mainobject of the invention to utilize water ballast in building foundationsof this class, and at the same time to attain economy, speed andconvenience in placing and building structures of this class. Toaccomplish these objects I incorporate in my* improved pier and pierfoundation as an integral part thereof a concrete tubular shell,substantially cylindrical, armed with a cutting shoe, and having coaxialinner and outer walls with a plurality of pockets for temporary ballastbetween the walls.

In the accompanying drawings, illustrating the best mannery in which Ihave contemplated applying the principles of the invention, Fig.

" l is a side elevation of a typical pier consisting of twin piers andfoundations which are singly constructed in accordance with theseprinciples and are braced together. Fig. 2 is an incomplete sideelevation of one of these twin piers and foundations, partly in verticalaxial section. Fig. 3 is a horizontal cross section on the section line3-3 -of Fig. 2.

To build and locate my improved pier and pier foundation in individualform I first '1, provide a unitary base portion thereof which tion thisshell is reinforced by a suitable steel is shown in section in Fig. 2.This base portion, which is to become an integral part of the completedstructure, is a hollow columnar concrete casting, is long enough toextend at one and the same time into the air above the water and intothe soil below, and is adapted to right itself to a vertical positionwhen afioat. It is towed to position while partly submerged and whilesupported by its water displacement. It is a tubular shell,substantially cylindrical, open from end to end, and double-walled,comprising the outer wall 2 and the inner wall 3. These walls arecoaxial with the central dredging passage 6, and are united at thebottom of the shell in a sharp circular edge armed with the annularcutting shoe 7 In the shown specimen of the invenframe l imbeddedtherein, comprising truss bracing encased in concrete partitions 4, by

which the space between the walls is uniformly divided into a series, orendless train, of ballast pockets 5 which individually reach from thebottom to the top of the shell. These concrete partitions, which areomitted from Fig. 2 for the sake of clarity, are plainly seen in Fig. 3.The lower end portion of the outer wall 2 is larger around than itsupper portion and is united therewith by an intermediate frustrum-likeportion 8, which tapers upward from the sect-ion line 3 3, as shown inFig. 2; while the inner wall 3 has its upper and principal portioncylindrical, and its bottom portion 9 flaring, like an inverted funnel.Alternate pockets 5 may be filled with concrete, and the rest of thepockets may be loaded temporarily with water ballast by siphons,sea-cocks, or other means. Weighted by the contents of these pockets,which are shown empty in the drawings, the shell, after being towed toposition and anchored there, naturally sinks through the water andforces the cutting shoe 7 into the soft bottom. During this sinking ofthe structure its tendency to list in any direction from its verticalposition is curbed and counteracted by the resistance of earthymateria-l within and against the flaring portion 9 of the dredgingpassage G-a force which arises from the inertia of that material. Thesinking of the structure is further controlled and its tendency to listin any direction is resisted, as occasion may require, by selectivelyvaiyin from time to time the amount of water bal ast in the severalpockets 5, and by distributing the same mainly to that side of the shellwhich encounters for the time being the chief resistance to sinking.Dredging may be carried on through the central passage 6 in the usualmanner, as with clamshell or orangepeel bucket-s, while the sinkingcontinues, and until the cutting shoe 7 reaches firm material. Meanwhilethe described shell is continued upward by concrete additions integrallyunited therewith at the top of the shell. Then the soft or loosematerial is cleaned from the fia-ring inner surface 9, and the bottom ofthe dredging passage is sealed, as with a treenail or with concretedeposited through the water by flatbottoni buckets to the sufficientdepth of several feet. rlhe structure is then unwatered and the laitanceand inferior top stratum of the contained concrete, if any, are removedfrom the dredging passage. The partly filled and the empty ballastpockets 5 and the llO dredging pocket 6 are then iilled up to tbe top ofthe pier with concrete, wherein rock may be imbedded if desired.

I claim as my invention- In a structure of a speoilied class a tubularshell comprising two coaxial Walls armed with a cutting shoe and havinga plurality of ballast pockets between the Walls, the inner wall beingflaring. at the bottom and substantially cylindrical above,.and theouter Wall having a substantially cylindrical upper por tion, asubstantially cylindrical bottom portion and an intermediatefrustrum-like portion.

Witness my signature at Minneapolis, Minn., December 16th, 1927.

CLAUDE A. P. TURNER;

